Title II. Sacred Times
Can. 1244 §1. It is only for the supreme ecclesiastical authority to establish, transfer, and suppress feast days and days of penance common to the universal Church, without prejudice to the prescript of can. 1246, §2.
§2. Diocesan bishops can decree special feast days or days of penance for their dioceses or places, but only in individual instances.
Can. 1245 Without prejudice to the right of diocesan bishops mentioned in can. 87, for a just cause and according to the prescripts of the diocesan bishop, a pastor can grant in individual cases a dispensation from the obligation of observing a feast day or a day of penance or can grant a commutation of the obligation into other pious works. A superior of a religious institute or society of apostolic life, if they are clerical and of pontifical right, can also do this in regard to his own subjects and others living in the house day and night.
Chapter I. Feast Days
Can. 1246 §1. Sunday, on which by apostolic tradition the paschal mystery is celebrated, must be observed in the universal Church as the primordial holy day of obligation. The following days must also be observed: the Nativity of our Lord Jesus Christ, the Epiphany, the Ascension, the Body and Blood of Christ, Holy Mary the Mother of God, her Immaculate Conception, her Assumption, Saint Joseph, Saint Peter and Saint Paul the Apostles, and All Saints.
§2. With the prior approval of the Apostolic See, however, the conference of bishops can suppress some of the holy days of obligation or transfer them to a Sunday.
Can. 1247 On Sundays and other holy days of obligation, the faithful are obliged to participate in the Mass. Moreover, they are to abstain from those works and affairs which hinder the worship to be rendered to God, the joy proper to the Lord’s day, or the suitable relaxation of mind and body.
Can. 1248 §1. A person who assists at a Mass celebrated anywhere in a Catholic rite either on the feast day itself or in the evening of the preceding day satisfies the obligation of participating in the Mass.
§2. If participation in the eucharistic celebration becomes impossible because of the absence of a sacred minister or for another grave cause, it is strongly recommended that the faithful take part in a liturgy of the word if such a liturgy is celebrated in a parish church or other sacred place according to the prescripts of the diocesan bishop or that they devote themselves to prayer for a suitable time alone, as a family, or, as the occasion permits, in groups of families.
Chapter II. Days of Penance
Can. 1249 The divine law binds all the Christian faithful to do penance each in his or her own way. In order for all to be united among themselves by some common observance of penance, however, penitential days are prescribed on which the Christian faithful devote themselves in a special way to prayer, perform works of piety and charity, and deny themselves by fulfilling their own obligations more faithfully and especially by observing fast and abstinence, according to the norm of the following canons.
Can. 1250 The penitential days and times in the universal Church are every Friday of the whole year and the season of Lent.
Can. 1251 Abstinence from eating meat or some other food according to the prescripts of the conference of bishops is to be observed on every Friday of the year unless a Friday occurs on a day listed as a solemnity. Abstinence and fasting, however, are to be observed on Ash Wednesday and Good Friday.
Can. 1252 The law of abstinence binds those who have completed their fourteenth year of age. The law of fasting, however, binds all those who have attained their majority until the beginning of their sixtieth year. Nevertheless, pastors of souls and parents are to take care that minors not bound by the law of fast and abstinence are also educated in a genuine sense of penance.
Can. 1253 The conference of bishops can determine more precisely the observance of fast and abstinence as well as substitute other forms of penance, especially works of charity and exercises of piety, in whole or in part, for abstinence and fast.